A shock absorber in a leg prosthesis should be able to absorb linear as well as rotational forces which occur at heel strike when the foot hits the ground during activities such as walking, running, jumping etc. During walking and at heel strike the shock damping function of the artificial foot and sometimes also of the artificial knee is often unsufficient. However at such movements when the whole foot at the same time strikes the ground, e g when jumping and at quick movements such as running, there is needed a further shock absorption in order to avoid unpleasant shocks transferred to the part of the body to which the prosthesis is applied. Such shock absorbers which normally are placed in the lower leg part of the prosthesis often consist of hydraulic or pneumatic devices, which are relatively complicated and expensive.
In the leg prosthesis there is further needed a torque absorber which absorbs rotational movements in the artificial foot with respect to the leg prosthesis. One example of such a torque absorber is disclosed in U.S. Pat. No. 4,038,705.